Furnace.



PATENTIEDY'JUNIE 19, 1906.

'J. P. MoLEOD. FURNACE.

APPLICATION FILED SEPT. 16, 1905 'fiz 6762507 UNITED- STATES- .JOII P.

PATENT OFFICE. I McLEOD, or CHICAGO, ILLINOIS, ASSIGNOR F. ONE-HALF. TO HERMAN r. vosIIARnT, or CHICAGO; ILLINOIS.

FURNACE.

To all whom it may concern: v i i Be it known that 1, JOHN P. MeLnon,' a

citizen of theUnite'd States, residing at 'Chi- -,ca'go, in the county of Cook and State of IllinoIs, have'invented new and useful Improvements in Furnaces, of which the following is :a specification, reference being had to the accom anying drawingsforming a part thereof.

T e purposj'e olfthis Invention is to provide an improved ifurnace particularly designed for steam-boilers forthe purpose of improving combustion and preventing any combus- .tible products. of the fuel being carried off in T have shown in the drawings a familiar construction and arrangement of fire-box, boiler, bridge-wall, and smoke-discharge passages.

Arepresents theboiler; B, the grate; C, the

fire-box above the grate; D, the ash-pit; E,

the brid e-wall at the rear of the grate; F, the smokeischarge pipe, which leads to the smoke-stack G.

H is a dam er in the smoke-discharge pipe F. Back of t e damper Hthat is, between said damper andthe furnace -a pipe J leads oil from the smoke-pi e F to the intake of a fan K. In the pipe ,l there is interposed a cut-0H valve or ampere- J. Between the cut-off valve or damper J and-the fan the pipe J is provided with an air-inlet J and a valve or damper J governin I A pipe L, leading from the ischarge of the fan K, is branched or forked one branch L extending toward' the fire-box and being again branched or forked, one branch L 9, leading through the furnace-wall above therate Into the fire-box proper, and another l iranch Lu leading throu h the furnace-wall into the ash-pit. The ot er branch L oftlie pipe L leads oil from the lower side of said pipe L, said 1pipe being enlarged to form 'a trap-pocket at the lower side and the branch L leadingfrom'the end of this trappocket off to the smoke-stack G, a regulating Specification of Letters Patent. Application-filed September 16, 1905- sQflll NO. 278,695- I 1y of the fire-box and certain.

of coals.

such air-inlet.

Patented June 19, 1908.

valve or dam er M being interposed in said branch L. he purpose ofthisbranch Lis to conductthe s ent orv perfectly-consumed gases, chiefly ear onic-acld gas, to a pint be' r yond the damper H, and thus i'ntot e stack while the branch L conducts the lighter and less perfectly consumed or unconsumed gases The gases which are re-' turned to the furnace through the branch L back to the fire.

having become mixed with. air 'deriv through the air-inlet J are ready for perfect '65 combustion when theyare discharged mto' the fire, either throughthe' bran'ch Ll, cansmg them to pass up through the bed -:offcoals coals in the fire-box'proper. The means for discharging and distributing the intermixed 'on the grate or throu h the branch L', which causes them to bedlscharged above the'bed of air and'returned gases which are delivered i. through the branch L above the fire consists of a reheatin or 'sugprheating, box" or chaniber N. This ox or c amber is made of cast-Iron and is mounted immediately above the fuel-door at the forward side of the firebox, extendin 'across the fire-box substantially from en to end. On the rear side this box is provided with slots mm m for discharge of the mixed air and gases downwardand rearward onto the fire or into the hot products of: combustion rising from the bed The position of this distributing and reheating box is such that it is intensely I heated, and the gases returned through the pipe L and somewhat cooled in their passage and further cooled by the intermixture of fresh air with them are reheated so as to be ready for instant and when they are discharg into the other hot gases risin from the coals. The quantity of air which t ey carr derived in their passage,

through the pipe bein preferably somewhat more than required or their own complete combustion, and this air, as well as the gases bein heated in its passage through the I ox N, an particularly when it isdischarged through the narrow discharge-slots m, its

9 I erfect combustion presence above the coals in the fire-box assists the combustion of the fresh. gases developed from the coals, so that the proportion of imperfectly-consumed gas .to be returned through the pipe L tends todiminish somewhat after the return of the gases and their discharge through, the box N commences.

In. operating this device upon starting the which will be hereinafter explained, being at the lower side of the pipe L and the gases being somewhat cooled by the time they have reached this point, the carbonic-acid gas and, in the main, all the gases which resalt from more perfect combustion settle into thelowerspart of the pipe L and are drawn into this trap ,lfandpass out by the naturaldraft through the pipe L into the stack G, leaving the remainder, comprising all the im rf ectly-consuined gases, to pass through t e pipe L and be discharged in part below the grate and in part above the grate to complete their combustion by passing again through the fire-box, where the air which they carry further assists the original combustion of new fuel. The pipe J preferably takes off from the upper side of the p e F, so that the heavier and more perfectly consumed gases coming in the first instance from the furnace and tending to follow the lower side of the pipe will pass directly into .the'stack, and the damper H is for like reason preferably made to close from above downward, so that when partly open the aperture will be at the lower side 0 the pipe. The same result may be further assisted by locating a trap F, similar to the trap L at the lower side of the pipe F, between the damper H and the furnace and leading a pipe F from it to the stack, thus making a by-pass around the damper H to the stack. By this means practically all exce t the perfectly-consumed gases are excluded cm the stack and caused to pass back over the fire until they become consumed, so as to fall into the traps L and F and be discharged thence to the stack.

'1. In a furnace, in combination with the firebox, smoke pipe and stack, a cutoff or damperin the smoke-pipe; an exhaust de vice and pipe connecting its intake with the smokepipe back of the damper having an air-inlet and means for regulating the same; a dischargepipe from the exhaust device leading to the firebox; a h'c-avygas trap in thesmolre-pipe back of the damper and a discharge connection from the trap lea-ding past the damper for final discharge into the stack a heavy-gas trap in the discharge-pipe from the exhaust device and a branch pipe leading from the tra havin connection for discharge beyond t e sino e-pipe damper into the stack.

' I 2. In a furnace, in combination with a passage-by which the smoke is conducted on its way to the stack, a damper in such passage; connections leading from such passage back of the damper for conducting the gases back to the fire-box; a heavy-gas trap located at the lower side of a substantially horizontal portion of such passage back of the damper, said trap comprising at its upper part bafileplates trending obliquely onward and downward into the trap-space, and a dischar 0 connection leading from the trap beyond t 10 bafile-plates past the smoke-pipe damper for final discharge into the stack.

3. In a furnace, in combination with a passtage by which the smoke is conducted on its way to the stack, a damper in such passage; a heavy-gas trap located at the lower side of a substantially horizontal portion of such passage back of the dam er, said trap comprising at its upper art hams-plates trending obliquely onwar and-downward into the trap-space, and a discharge connection leading from the trap beyond the bafiielates past the smoke-pipe damper for iina discharge into the stack; an exhaust device and a pipe connecting its intake with said horidental portion of the smoke-pipe at the up er side thereof back of thedamper, and a rischarge-pipe from said exhaust device leading to the firebox. Y

t. In a furnace, in combination with a passage by which the smoke is conducted on its Way to the stack, a smoke cuboil or damper in the smoke-pipe an exhaust device; a pipe connecting its intake with the smoke-pipe back of the damper and having an air-inlet and means for regulating the same; a dischargeipe from the exhaust device leading to the lire-box having a substantially horizontal portion and a heavy-gas trap located at the lower side of said substantially horizontal portion, said trap comprising at its upper part baffle-plates trending obliquely onward and downward into the trap-space, and a discharge connection loading from the lower side of the trap past the smoke-pipe damper for final discharge into the stack.

In testimony whereof l. have hereunto set my hand, in the presence of two witnesses, at Chicago, Illinois, this 11th day of September, 1905.

L. M. SMITH, J. S. Asnor'r. 

